Hello!
It is possible, but I personally would not introduce them until the younger chick is larger and more able to defend itself. I would also introduce 2 or more chicks to an established group because that makes it harder for the older birds to pick just one target for their bullying. I think the see-but-don't-touch method would work. You would just have to watch them once they are introduced to make sure the older chicks are not beating up the younger ones too badly. If done correctly it could work, but I really wouldn't introduce new birds to a flock unless they were very close in size. I typically don't introduce my younger birds into my main flock until they are 3-4 months old.
